docs: def get_vcs_root():
      """Returns the vcs module and the root of the repo.
  
      Returns:
        A tuple containing the vcs module to use (git, hg) and the root of the
        repository. If no repository exisits then (None, None) is returned.
      """
      for vcs in (git, hg):
          repo_root = vcs.repository_root()
          if repo_root:
              return vcs, repo_root
  
      return (None, None)